The closure seal and container industries are constantly striving for improvements to better seal and contain products, particularly liquid products or food products that are susceptible to spoilage or contamination. Accordingly, zero leakage and total containment of container contents is the ultimate goal. The closure and container industry have been able to provide sealing arrangements that do, for the most part, perform an adequate sealing and containment function. However, there remains room for improvement. Another factor that influences the sealing and containing features of containers is the manufacturing processes, which are themselves far from flawless.
In manufacturing the containers and the closures, the blow molding, extrusion or other processes used to make them, are apt to create imperfections either in the upper surface of the closure or, more typically, on the land surface of the container mouth. These imperfections, such as bubbles, holes, lumps and the like, can interfere with the proper sealing of the closure to the container, thereby rendering the sealing arrangement partially or fully ineffective. To alleviate this problem a second or base liner is often used to improve the seal and counter any imperfections on the container mouth or in the closure. Also, various arrangements of sealing beads, ribs or abutments, either alone or in combination with liners, have been used to increase the sealing engagement between the closure and the container mouth. Although effective, these inventions have not solved the problem entirely.
Accordingly, there is a strong need for a sealing arrangement between the container mouth and the closure that will increase sealing and containment without increasing manufacturing costs or requiring complex manufacturing techniques.